Graft polymers

ABSTRACT

Method for producing graft polymers from a cyclic olefin as graft monomer and from a polymer containing carbon-carbon double bonds as the grafting base wherein the grafting reaction is effected by a catalyst comprising A. A COMPOUND OF A METAL OF Group VB or VIB of the Mendeleev Periodic System, and B. AN ORGANIC COMPOUND OF A METAL OF Group IA to IIIA of the Mendeleev Periodic System. AND GRAFT POLYMERS OBTAINED IN THIS PROCESS.

United States Patent Pampus et al.

GRAFT POLYMERS Inventors:

Assignee:

Filed:

App]. No.:

Gottfried Pampus, Leverkusen; Josef Witte, Cologne-Stammheim; MartinHoffmann, Bergedorf- Gladbach, all of Germany Bayer Aktiengesellschaft,Leverkusen, Germany Dec. 21, 1971 Related US. Application DataContinuation-impart of Ser. No. 72,790, Sept. 16, 1970, abandoned.

Foreign Application Priority Data Oct. 28, 1969 Germany 1954092 Apr. 7,1970 Germany 2106471 US. Cl. 260/879, 260/878 R Int. Cl......

................. C08f 15/04, C08f 19/08 Field of Search 260/879, 94.7D, 93.1

References Cited UN [TED STATES PATENTS DallAsta 260/853 X Mar. 25, 19753,631,010 12/1971 Witte et a1. H 260/931 3,632,849 1/1972 Pampus et a1.

3,649,709 3/1972 Medema et a]. 260/680 R 3,707,520 12/1972 Pampus et al.260/879 X Primary ExaminerHarry Wong, .lr. Assistant E.raminerMaria S.Tungol Attorney, Agent, or FirmConnol1y and Hutz 57 ABSTRACT 6 Claims,N0 Drawings GRAFT POLYMERS This application is a continuation-in-part ofapplication Ser. No. 72,790 filed Sept. 16, 1970, now abandoned.

It is known that cyclopentene, in the presence of organometallic mixedcatalysts based on organic aluminium compounds -O-tungsten salts, canundergo ringopening and polymerisation, to form linear high molecularweight unsaturated hydrocarbons whose carboncarbon double bonds have forthe most part a transconfiguration.

British Patent Specification No. 1,010,860 relates to a process for thebulk polymerisation of cyclopentene accompanied by ring-opening and theformation of trans-polypentenamers. Unfortunately, this process has aserious disadvantage which makes it extremely difficult to work on acommercial scale. The bulk polymerisation reaction results in theformation of such highly viscous reaction mixtures that it is impossibleto control temperature during the polymerisation reaction. In addition,the polymerisation reaction can only be continued up to relatively lowconversions, for example from 20 to 50%, if it is desired to obtain anuncrosslinked, processible polymer. At higher conversions, insolublecrosslinked products are obtained which are of no commercial interest.

The present invention relates to a process for the production of graftpolymers from an unsaturated polymer as graft base and a cyclic olefinas graft monomer, in which a cyclic olefin is ring-opened andpolymerised with a polymer containing carbon-carbon double bonds,dissolved in an inert organic solvent, in the presence of a catalystcomprising:

a. a compound ofa metal of Group VB or VIB of the Mendeleev PeriodicSystem, and

b. an organic compound of a metal of group IA to 111A of the PeriodicSystem.

Examples of compounds of metals of groups VB and WE of the PeriodicSystem include halides and oxyhalides such as fluorides, chlorides,bromides, iodides and corresponding oxyhalides of vanadium, niobium.tantalum, chromium, molybdenum and tungsten and alkali metal (preferablypotassium) salts of chlorotungsten acids or chloromolybdenum acids.

Examples of organic compounds of metals of groups 1A to 111A of thePeriodic System include alkyl, alkoxy and halogenoalkyl compounds ofaluminium; alkyl and halogenoalkyl compounds of magnesium and beryllium;and alkali metal alkyls (for example of Na, K and Li), alkyl and alkoxyhaving preferably 1 12 carbon atoms.

The invention also relates to graft copolymers comprising from 0.1 to 90by weight, based on the total polymer, of a diene homopolymer orcopolymer as graft base, and from 99.9 to by weight of a cyclic olefingraft polymerised with ring-opening.

Examples of polymers containing carboncarbon double bonds which aresuitable as grafting bases in the process of the invention includehomopolymers and copolymers of conjugated dienes, preferably thosehaving 4 8 carbon atoms, for example of l,3'butadiene, isoprene,piperylene and 2-chlorobutadiene, for instance, 1,2-polybutadiene, cis-l,4-polybutadiene, 1,2- and 3,4- polyisoprene, cisl ,4-polyisoprene,poly-2- chlorobutadiene, and random or block copolymers of suchconjugated diolefins and a monoolefinically unsaturated copolymerisablecompound. Examples of such 2 compound are aromatic monovinyl compoundssuch as styrene, a-methylstyrene, vinyltoluene, chlorostyrene andaliphatic monovinyl compounds such as alkyl esters (alkyl C -C ofacrylic and methacrylic acid (e.g. methylmethacrylate, ethylacrylate,tert.- butylacrylate)and acrylic acid and methacrylic acid nitriles suchas acrylonitrile. Most preferred are copolymers of styrene andbutadiene, whose butadiene unitsv are incorporated in the 1,4- and/or1,2-position. The weight ratio of styrene to butadiene is from 95:5 to5:95.

The following are also suitable: ethylene-propylene terpolymerscontaining, for example, from 20 to parts by weight of ethylene and from80 to 20 parts by weight of propylene and, in addition, up to 20 partsby weight of a third component. Examples of suitable third componentsinclude l,5-hexadiene, 1,4-hexadiene, dicyclopentadiene, norbornadiene,methylene norbornene and ethylidene norbornene. Other unconjugateddienes are, of course, also suitable.

Suitable cyclic olefms include those with 4 to 20, preferably 5 to 12carbon atoms in the ring (except cyclohexene) and one carbon double bondor 2, 3 or more unconjugated carbon double bonds, such as cyclobutene,cyclopentene, cyclooctene, cyclododecaene, cyclooctadiene-l ,5,cyclododecatriene-1,5,9, cyclopentene being preferred.

Catalysts comprising a compound of a metal of group VB or VIB of thePeriodic System and an organic compound of a metal of groups 1A to 111Aof the Periodic System are used in the process according to theinvention. It is preferred to use a catalyst comprising:

a. a tungsten, tantalum or molybdenum halide or oxyhalide, such asfluorides, oxyfluorides, chlorides, oxychlorides, bromides, oxybromides,iodides and oxyiodides e.g. WF WBr WCI WJ WCl O, WBr,O, MoCl MoCl MoClO, MoBr MoBr O, M01 TaCl TaF TaBr Tal TaCl O, TaBr O b. anorganoaluminium compound of the formula wherein R, represents alkylhaving 1 to 12 carbon atoms, R and R represent ihdepently hydrogen,alkyl having 1 to 12 carbon atoms, halogen such as fluorine, chlorine,bromine, or iodine, alkoxy having 1 to 12 carbon atoms. Examples of suchcompounds are aluminium trialkyl, for example Al(C H Al(C l-l or Al-(isoC H aluminium halogen alkyl, for example H5)2Cl, Ai(C2H5)2 Br,H5)Cl2; 0r Al(C l-l l, aluminium alkoxyl alkyl, for example (C2H5)2C2H5- Tungsten halides are particularly preferred as compound (a).

The molar ratio of(a) to (b) is preferably from 1:05 to 1:15. Theactivity of the catalyst can be increased by co-catalysts which can beadded' in a molar ratio of component a):co-catalyst'of 1:0,3 to 1:10.Examples of co-catalysts such as these include:

.7 p x qis semasqnqspflhs general formulw X =H, alkyl having 1 to 6carbon atoms, aryl having 6 to carbon atoms or aralkyl (alkyl moiety 1to 6 carbon atoms, aryl moiety 6 to 10 carbon atoms) Y X, CH Hal(l-lal=Cl, Br or I) or CH -OR (R alkyl or aryl as defined in X) 2.halogen-containing alcohols of the general formula:

ill which in which Z is as defined above, each R represents an alkyl (C-C aryl (C -C 0) or a fused aromatic radical, and

n represents a number from 1 to 4, and

m is 0 t0 4, preferably 0 or 1.

Examples of suitable co-catalysts include ethylene oxide, propyleneoxide, epichlorhydrin, butadiene monooxide. phenoxypropylene oxide,glycidylether, isopropylglycidylether, 2-chlorethanol, 2-bromethanol,2-iodoethanol, l,3-dichloro-Z-propanol, 2- chlorocyclohexanol,2-chlorocyclopcntanol, o-, m or p-chlorophenol and o-, morp-bromophenol.

To prepare these catalysts, the tungsten salt can be reacted with theco-catalyst in the presence ofa hydrocarbon as solvent, usually in thesame solvent in which the polymerisation reaction is carried out, andapproximately 0.05 to 0.5 molar solutions are used.

The quantity in which the catalyst is used generally corresponds to from0.1 to 4 mMol of the metal of Group VB or VlB per 100 g of monomer.

The process can be carried out by successively adding the catalystcomponents to a solution of the cyclic olefin and the polymer containingcarbon-carbon double bonds in a suitable solvent, and then allowing thepolymerisation reaction to take place. There is no need for separatepreparation of the catalyst. The polymerisation reaction is preferablycarried out in the absence of air and moisture, for example in an inertgas atmosphere (e.g. nitrogen or argon). The order in which the catalystcomponents is added is not critical, although the following sequence ispreferred: component (a)/co catalyst/component(b).

The catalysts can be prepared at temperaturescf from 60 to +60C, andpreferably at temperatures of from ---20 to +20C.

It can be of advantage to react the tungsten salt, for example tungstenhexachloride, with the co-catalyst initially in a small proportion ofthe solvent used for the polymerisation reaction, because it is possiblein this way to obtain much more concentrated solutionsof the tungstencompound. This solution can then be added to the solvent-monomer-polymermixture, followed by component (b), e.g. an organoaluminium compound.Polymerisation begins immediately following the addition of theorganoalum'inium compound. The polymerisation temperature can be in therange from 60 to +60C, although it is preferably in the range of from 20to +20C. The polymerisation time is usually from I to 5 hours.

The polymers containing carbon-carbon double bonds are dissolved, forexample, in a proportion of the hydrocarbon used as the polymerisationmedium. These solutions are generally added to the monomer solutionbefore the catalyst components are introduced. These solutions can,however, also be added at any time during polymerisation of the cyclicolefin.

The unsaturated polymer used as graft base can preferably be employed ina quantity of from 0,1 to 90 by weight, and most preferably from I to 20by weight, based on the cyclic olefin.

Solvents suitable for use in the process include allphatic hydrocarbonssuch as butane, pentane, isooctane, hexane; cycloaliphatic hydrocarbonssuch as cyclohexane; or aromatic hydrocarbons such as benzene, tolueneor Xylene. It is possible to employ from 5 to 50 weight-% solutions ofcyclopentene in the aforementioned solvents for the process. The processis preferably carried out with monomer concentrations of from 10 to 30wt.-%.

The process can be carried out either continuously or in batches.

The products obtained by the process described in the foregoing differin their properties, depending on the type and quantity of graft baseused. The products can be crosslinked, for example, with radical formersor sulphur-containing systems, and may be used in the production ofelastomeric materials. This applies especially when small quantities ofgraft base are present in the graft polymer, for example from (H to 20wt.-%, based on the total polymer. With larger quantities of graft base,especially more than 50 wt.-%, it is possible to obtain thermoplasticproducts of high impact strength. The properties of the graft polymersare also influenced by the type and composition of the graft base. Themore resin-like the graft base (for example high styrene content), themore noticeable the thermoplastic properties.

EXAMPLE 1 a. Preparation of 1,2-polybutadiene 20,000 ml of benzene and2500 g of butadiene are introduced into an autoclave equipped with astirring mechanism. The mixture has a water content-of 1.8 ppm. 10.7 mlof glycol dimethyl ether and mM of n-butyl lithium, in the form of al-molar solution in hexane, are then added at 8C. On completion ofpolymerisation, the product is precipitated with methanol, stabilisedwith 2,6-di-tert-butyl-4-methyl phenol (0.2%) and dried in vacuo at 50C.The conversion amounts to 98.5%; (n) toluene, 25C 0.65; 1,2-bondcontent: 78%.

b. Graft polymerisation of cyclopentene on to 1,2- polybutadiene g of1,2-polybutadiene (according to a) are dissolved .in 900 ml of drytoluene in a vessel equipped with a stirring mechanism. 200 g ofcyclopentene are then added. Following the addition of 1.6 mM of thereaction product of tungsten hexachloride and chlorethanol in a molarratio of 1.0 (in the form of a 0.05 molar solution in toluene), themixture is cooled to -5C. Polymerisation begins immediately followingthe addition of 3.5 mMol of aluminium d iethyl monochloride. Thepolymerisation temperature can be increased to +5C over a period of 4hours. Polymerisation is then stopped by the addition of 0.5 ml ofethanolamine, 20 ml of ethanol, 1 g of 2,2-dihydroxy-3,3-di-tert-butyl-5,5-dimethyl diphenylmethane dissolved in 100 ml of toluene. The graftpolymer is precipitated with ethanol and dried in vacuo at 60C.

The yield comprises 74%; (17) toluene, C 1.84; ML 4.'/l00: 52; Defo(80C): 650/37.

Physical-chemical investigation of the graft polymer by turbiditytitration and precipitation fractionation, and examination of thefractions to determine their 1R extinction and refractive index at 60C,show a degree of grafting of 100%.

Turbidity titrations: solutions of 5 mg of polymer in methylene chlorideare titrated with methanol at 35C, single-peak solubility distributionsbeing obtained in the case of polybutadiene and the graft polymers.

Fractionation: 1% benzene solutions are subjected to fractionalprecipitation at 40C by the addition of methanol and left to settleovernight at 25C. The fractions are recovered by decantation and dried.Their refractive index at 60C can readily be determined with an Abberefractometer. The decadic extinctions of films of these fractions weredetermined at 11 p. and 10.35 p. and compared with one another. Theratio is substantially proportional to the polybutadiene component.

The intrinsic viscosities of the fraction were determined in toluene at25C.

The graft polymer described above gave the following analytical data:

Considerable quantities of polybutadiene are found in fractions 1, 3 and5 by infra-red analysis. None of the fractions has a refractive indexwhich is close to that of the polybutadiene; in other words, it was notpossible to isolate ungrafted polybutadiene.

The fact that the polybutadiene components of very different fractionsare comparable in size, and the fact no ungrafted polybutadiene could beisolated. shows that all the polybutadiene was grafted.

EXAMPLES 2 4 2 to 10 parts by weight of 1,2polybutadiene (according toExample la) are dissolved in 1300 parts by volume of dry toluene in avessel equipped with stirring mechanism. 200 Parts by weight ofcyclopentene are added to the solution in the absence of oxygen andmoisture. This is followed by the addition at room temperature of 3.5parts by volume of a 0.2 molar solution (based on tungsten) of areaction product of WCl and epichlorohydrin in a molar ratio of 1:2 intoluene, after which the mixture is cooled to 10C. 2.2 Parts by volumeof a l-molar solution of Al(C- H Cl in toluene are then added.Polymerisation begins immediately and, following a gradual increase intemperature to +5C, is stopped after 3 hours by the addition of 1 partby weight of ethylene diamine and 0.5 part by weight of2,6-di-tert-butyl-4-methylphenol dissolved in 20 parts by volume oftoluene. The polymers are precipitated with ethanol and dried in vacuoat 60C.

The reaction conditions are set out in the following table:

It is clear from the viscosity data that the degree of branching throughgrafting increases with an increase in the quantity of 1,2-polybutadienemixture (decrease in solution viscosity ('0) and increase in Defohardness and elasticity).

EXAMPLE 5 a. Preparation of a butadiene-styrene copolymer A mixture of gof butadiene and 165 g of styrene is dissolved in 3000 ml of toluene. 36mlof glycol dimethyl ether and 3 to 6 mM of n-butyl lithium are thenadded at 0C in the absence of oxygen and moisture. Polymerisation iscarried through to completion at 40C. The copolymer is stabilised with0.1% of 2,6-ditert-butyl-4-methylphenol. precipitated with ethanol anddried in vacuo at. C.

Conversion: 98%; (n) toluene 25C 0.3.

b. Graft polymerisation 20 g of the copolymer prepared in accordancewith 5a are dissolved in 900 ml of dry toluene and grafted withcyclopentene as described in Example lb. The product is then worked upas described in Example lb.

EXAMPLE 6 20 g of a block copolymer of butadiene-styrene (50:50 moll,4-component in the butadiene block 88%, (11) 0.3) are dissolved in 900ml of dry toluene. The further procedure is then as described in Examplelb. A graft copolymer is obtained in a yield of 50%, based on thecyclopentene used, with a degree of grafting of 100%.

'The Defo hardness and elasticity (at 80C) were 2650/38, whilst theintrinsic viscosity (1 toluene 25C was 2.19.

A comparison test carried out in the absence of the graft base producesa rubber-like transpolypentenamer. Defo l 150:9 (80C), (1 toluene 25C3.04.

EXAMPLE 7 As in Example 1b, 50 g of a terpolymer of 42 parts by weightof propylene, 50 parts by weight of ethylene and 8 parts by weight ofdicyclopentadiene [(1 toluene 25C 2.7] are dissolved in 900 ml of drytoluene in a vessel equipped with stirring mechanism. 200 g ofcyclopentene are added. This is followed by the addition of 2.0 mMols ofa reaction product of tungsten hexachloride and epichlorohydrin in amolar ratio of 2.0 (in the form of a 10% solution in toluene) and 4mMols of diethyl aluminium chloride (in the form of'a l-molar solutionin tuluene). The reaction temperature is lC. The temperature is allowedto rise gradually to +l0C over a period of 3 hours. After the reactionproduct has been isolated by precipitation with 2000 ml of ethanol, agraft copolymer with an (17) value (toluene 25C) of 1.7 is obtained in ayield of 230 g.

It was established through fractionalprecipitation (benzene/methanol)and infra-red spectroscopy that the graft base was present in all thefractions.

We claim:

1. A process for the production of graft polymers which comprisespolymerizing, as graft monomer, a cyclic olefin containing 4, or from 7to 20 carbon atoms in the ring and having one carbon to carbon doublebond or two or more unconjugated carbon to carbon double bonds onto agraft base polymer containing carbon to carbon double bonds, saidpolymerization being carried out in an inert organic solvent at 60 to60C. and in the presence of a catalyst comprising a. a tungsten,tantalum or molybdenum halide or oxyhalide,

b. an organoaiuminum compound of the formula wherein R is alkyl having 1to 12 carbon atoms and R and R independently are hydrogen, alkyl having1 to 12 carbon atoms, halogen or alkoxy having 1 to 12 carbon atoms andc. a cocatalyst which is i. an epoxide of the formula wherein X ishydrogen, alkyl having 1 to 6 carbon atoms, aryl having 6 to l0 carbonatoms or aralkyl having 6 to 10 carbon atoms in the aryl moiety and l to6- carbon atoms in the alkyl moiety and Y is hydrogen, alkyl having 1 to6 carbon atoms, aryl having 6 to 10 carbon atoms, aralkyl having 6 to 10carbon atoms in the aryl moiety and 1 to 6 carbon atoms in the alkylmoiety,

iodine or CH2-OR wherein R is alkyl having l to 6 carbon atoms orarylhaving 6m 10 fl t ms 0r ii. a halogen-containing alcohol of theformula OHZ wherein Z is chlorine, bromine or iodine, R and R are thesame or different and are hydrogen, alkyl having 1 to 6 carbon atoms,chloroalkyl having 1 to 6 carbon atoms, aryl having 6 to 10 carbon atomsor aralkyl having 6 to 10 carbon atoms in the aryl moiety and 1 to 6carbon atoms in the alkyl moiety, R and R, are the same or different andare chlorine, bromine, iodine, hydrogen, alkyl having 1 to 6 carbonatoms, aryl having 6 to 10 carbon atoms or aralkyl having 6 to 10 carbonatoms in the aryl moiety and l to 6 carbon atoms in the alkyl moiety andR, and R when taken together with the carbon atom to which they areattached, form a 5- or 6-membered hydrocarbon ring, the molar ratioof(a) to (b) being 1:05 to 1:15 and the molar ratio of (a) to (c) being1:03 to 1:10.

2. A process as claimed in claim 1 wherein the graft and polymer.

-CH Hal wherein Hal is chlorine, bromine, or

1. A PROCESS FOR THE PRODUCTION OF GRAFT POLYMERS WHICH COMPRISES POLYMERIZING, AS GRAFT MONOMER, A CYCLIC OLEFIN CONTAINING 4, 5 OR FROM 7 TO 20 CARBON ATOMS IN THE RING AND HAVING ONE CARBON TO CARBON DOUBLE BOND OR TWO OR MORE UNCONJUGATED CARBON TO CARBON DOUBLE BONDS ONTO A GRAFT BASE POLYMER CONTAINING CARBON TO CARBON DOUBLE BONDS, SAID POLYMERIZATION BEING CARRIED OUT IN AN INERT ORGANIC SOLVENT AT -60 TO 60*C. AND IN THE PRESENCE OF A CATALYST COMPRISING A. A TUNGSTEN, TANTALUM OR MOLYBDENUM HALIDE OR OXYHALIDE, B. AN ORGANOALUMINUM COMPOUND OF THE FORMULA
 2. A process as claimed in claim 1 wherein the graft base is a diene homopolymer or copolymer.
 3. A process as claimed in claim 1 wherein the graft base is polybutadiene or a butadiene-styrene copolymer.
 4. A process as claimed in claim 1 wherein the graft base is an isoprene homopolymer or copolymer.
 5. A process as claimed in claim 1 wherein the cyclic olefin is cyclopentene.
 6. A process as claimed in claim 1 wherein the graft base is 0.1 to 90 % by weight of the total of monomer and polymer. 